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Vitamins and Hormones 1971
Review
Topics: Amino Acid Sequence; Amino Acids; Animals; Calcitonin; Cattle; Chromatography, Gas; Chromatography, Gel; Chromatography, Ion Exchange; Electrophoresis, Disc; Humans; Immunoassay; Parathyroid Hormone; Protein Conformation; Salmon; Sheep; Structure-Activity Relationship; Swine
PubMed: 4944057
DOI: 10.1016/s0083-6729(08)60047-3 -
Annals of Clinical Biochemistry Jan 1992
Review
Topics: Animals; Calcium; Circadian Rhythm; Female; Guinea Pigs; Humans; Male; Neoplasms; Parathyroid Hormone; Radioimmunoassay; Rats
PubMed: 1536518
DOI: 10.1177/000456329202900103 -
Journal of Orthopaedic Trauma Mar 2010Parathyroid hormone is a well-known regulator of calcium metabolism in the body. It binds to osteoblasts and assists in the regulation of bone turnover. Changes in...
Parathyroid hormone is a well-known regulator of calcium metabolism in the body. It binds to osteoblasts and assists in the regulation of bone turnover. Changes in parathyroid hormone levels have been documented in pathologic states such as osteoporosis, and fluxes are also noted during healing of fractures. Because fracture healing requires time and is sometimes unreliable, a search for fracture-healing adjuvants that accelerate the healing rate and improve reliability of healing is compelling. Parathyroid hormone, as a systemic mediator of calcium and bone metabolism, is a good candidate. Much research has been accomplished in animal models examining the role of parathyroid hormone in fracture healing. Although further research is required, especially in human fracture patients, early indicators are that parathyroid hormone may play a role in accelerating fracture healing in healthy patients and in reducing rates of fracture nonunion in compromised patients or tissue beds.
Topics: Bone and Bones; Fracture Healing; Fractures, Bone; Humans; Models, Biological; Parathyroid Hormone
PubMed: 20182232
DOI: 10.1097/BOT.0b013e3181cde5d1 -
Archives of Pathology & Laboratory... Nov 2003The rapid intraoperative parathyroid hormone assay is transforming the parathyroidectomy procedure. We present a review of the literature on the use of the assay as an... (Review)
Review
OBJECTIVE
The rapid intraoperative parathyroid hormone assay is transforming the parathyroidectomy procedure. We present a review of the literature on the use of the assay as an adjunct to surgery. To our knowledge, this is the first review of the literature to encompass and compare all known primary studies of this assay in parathyroidectomy patients.
DATA SOURCES
Articles were collected by searching MEDLINE databases using relevant terminology. The references of these articles were reviewed for additional studies. Supplementary articles pertinent to the parathyroidectomy procedure, preoperative parathyroid localization studies, and intraoperative parathyroid hormone assay development also were examined.
STUDY SELECTION AND DATA EXTRACTION
One hundred sixty-five references were analyzed and categorized separately into groups.
DATA SYNTHESIS
The primary studies of intraoperative data on patients undergoing parathyroidectomy were compared when possible. Studies were analyzed by type of assay used, where performed, turnaround time, and efficiency of use. Reviews of the types of parathyroid surgery and preoperative localization were included for educational purposes.Conclusions.-The intraoperative parathyroid hormone assay is a useful adjunct to preoperative imaging and parathyroid surgery because of its unique ability to detect an occult residuum of hyperfunctioning parathyroid tissue. Use of this assay will obviate the need for frozen section in most routine cases. The test facilitates minimally invasive parathyroidectomy for single parathyroid adenomas, which, in turn, improves cost-effectiveness and cosmetic outcome. Its use in patients with known preoperative multiglandular disease is promising but requires further study.
Topics: Humans; Intraoperative Care; Parathyroid Hormone; Parathyroidectomy
PubMed: 14567726
DOI: 10.5858/2003-127-1424-ITFPHA -
Obstetrical & Gynecological Survey Dec 2004Imbalances in bone metabolism result in bone mass loss and skeletal fragility in postmenopausal women and older men. Most osteoporosis treatments decrease bone... (Review)
Review
UNLABELLED
Imbalances in bone metabolism result in bone mass loss and skeletal fragility in postmenopausal women and older men. Most osteoporosis treatments decrease bone metabolism and prevent the progression of bone loss and architectural damage to the skeleton. Analogs of parathyroid hormone stimulate the formation of new bone and offer new options for managing osteoporosis. This review highlights the effects of parathyroid hormone on bone density and fracture risk in patients with osteoporosis and addresses several of the important issues pertaining to the use of these new agents in daily clinical practice.
TARGET AUDIENCE
Obstetricians and Gynecologists, Family Physicians.
LEARNING OBJECTIVES
After completion of this article, the reader should be able to summarize the different mechanisms of action between parathyroid hormone analogues and antiresorptive drugs, to outline the effects of teriparatide treatment of patients with osteoporosis, and list the indications of teriparatide therapy.
Topics: Female; Humans; Male; Osteoporosis; Parathyroid Hormone; Teriparatide
PubMed: 15572960
DOI: 10.1097/01.ogx.0000146584.12831.c9 -
Clinical Endocrinology 1976Many recent studies, only a few of which are reviewed here (see Habener & Potts, 1976, for a detailed summary) have led to considerable clarification concerning critical... (Review)
Review
Many recent studies, only a few of which are reviewed here (see Habener & Potts, 1976, for a detailed summary) have led to considerable clarification concerning critical features of the chemistry, biosynthesis, secretion and mode of action of parathyroid hormone. Certain of the confusion recently experienced in measurements of parathyroid hormone in blood is clearly explained by the heterogeneity arising from various forms of parathyroid hormone arising during biosynthesis and metabolism. Ultimately, as critical features of biosynthesis and metabolism of PTH as well as chemical definition of various molecular forms are achieved, considerable refinement in immunoassays should result. These advances in turn should provide better insights into the role of parathyroid dysfunction in various disorders of calcium and skeletal metabolism. From the physiological viewpoint, a clearer appreciation of the homeostatic role of parathyroid hormone in calcium metabolism is emerging as the essential features of biosynthesis, release, metabolism and action of the hormone are uncovered.
Topics: Amino Acid Sequence; Animals; Chemical Phenomena; Chemistry; Humans; Parathyroid Hormone; Peptide Chain Initiation, Translational; Protein Biosynthesis
PubMed: 802686
DOI: 10.1111/j.1365-2265.1976.tb03839.x -
Clinical Biochemistry Oct 1981The introduction of blood calcium determinations as part of routine health screening procedures in this country has led to the discovery of a much higher incidence of... (Review)
Review
The introduction of blood calcium determinations as part of routine health screening procedures in this country has led to the discovery of a much higher incidence of primary hyperparathyroidism than was recognized previously. Research efforts have focused on studies of the cellular defects in the regulation or parathyroid hormone biosynthesis and secretion that are characteristically found in adenomatous and hyperplastic parathyroid glands. The available evidence indicates that the secretory defect probably resides at two levels: (1) a defect in the calcium sensor of the abnormal glands ("set-point" error) and (2) an exaggeration of a small component of autonomous hormone secretion that becomes relevant due to the large mass of glandular tissue. Regulation of parathyroid hormone synthesis appears to be at the level of cell replication (hyperplasia) and at the level of intracellular turnover of hormone. Marked heterogeneity of hormone in the circulation arises as a result of both glandular and extraglandular cleavages of hormone and the predominant circulating form of the hormone are biologically inactive, COOH-terminal fragments. Because most cases of hypercalcemia that accompany cancer are caused by humoral substances other than COOH-terminal fragments should distinguish patients with hypercalcemia due to cancer from those with primary hyperparathyroidism.
Topics: Amino Acid Sequence; Animals; Calcium; Humans; Hyperparathyroidism; Models, Biological; Parathyroid Hormone; Protein Precursors; Radioimmunoassay
PubMed: 7037226
DOI: 10.1016/s0009-9120(81)90928-0 -
Biochemical and Biophysical Research... Oct 2021Novel human parathyroid hormone (hPTH) peptides of unknown biological activity have recently been identified in the serum of subjects with normal renal function, chronic...
BACKGROUND
Novel human parathyroid hormone (hPTH) peptides of unknown biological activity have recently been identified in the serum of subjects with normal renal function, chronic renal failure, and end-stage renal disease through the application of liquid chromatography-high resolution mass spectrometry.
PURPOSE
of experiments: To determine the bioactivity of these peptides, we synthesized hPTH28-84, hPTH38-84, and hPTH45-84 peptides by solid phase peptide synthesis and tested their bioactivity in MC3T3-E1 mouse osteoblasts, either individually or together with the native hormone, hPTH1-84, by assessing the accumulation of 3´,5´-cyclic adenosine monophosphate (cAMP) and the induction of alkaline phosphatase activity.
RESULTS
Increasing doses of hPTH1-84 (1-100 nM) increased the accumulation of cAMP and alkaline phosphatase activity in osteoblasts. hPTH28-84, hPTH38-84, and hPTH45-84 in concentrations of 1-100 nM were biologically inert. Surprisingly, 100 nM hPTH38-84 and hPTH45-84 increased the accumulation of cAMP in osteoblasts treated with increasing amounts of hPTH1-84. Human PTH28-84 had no effects on cAMP activity alone or in combination with hPTH1-84. Conversely, 100 nM hPTH38-84, hPTH45-84, and hPTH28-84 blocked the activation of alkaline phosphatase activity by hPTH1-84.
CONCLUSIONS
The data show that the short carboxyl-terminal hPTH peptides, hPTH38-84 and hPTH45-84, increase the amount of cellular cAMP generated in cultured osteoblasts in response to treatment with full-length hPTH1-84 when compared to full-length hPTH1-84 alone. Human PTH28-84 had no effect on cAMP activity alone or in combination with hPTH1-84. Human PTH28-84, hPTH38-84 and hPTH45-84 reduced the effects of hPTH1-84 in osteoblasts with respect to the induction of alkaline phosphatase activity compared to hPTH1-84 alone. Short carboxyl peptides of human PTH are biologically inert but when administered together with full-length hPTH1-84 modulate the bioactivity of hPTH1-84 in osteoblasts.
Topics: 3T3 Cells; Animals; Cells, Cultured; Mice; Osteoblasts; Parathyroid Hormone; Signal Transduction
PubMed: 34332324
DOI: 10.1016/j.bbrc.2021.07.085 -
Clinical Chemistry and Laboratory... Nov 2015Parathyroid hormone (PTH) is a major player in phosphocalcic metabolism and its measurement is very important for the correct diagnosis and treatment of several...
Parathyroid hormone (PTH) is a major player in phosphocalcic metabolism and its measurement is very important for the correct diagnosis and treatment of several diseases. PTH determination represents the paradigm of quality in laboratory medicine as many variables in the pre-, intra-, and post-analytical phases strongly affect the value of the clinical information. Analytical determination of PTH has been rendered difficult by the presence, in the circulation, of truncated fragments that can cross-react with the antibodies used for its determination. In addition, pre-analytical phase is complicated by the lack of stability of the peptide and the best sample to use for its determination remains controversial, as well as sample handling and storage. PTH secretion is also affected by circadian and seasonal rhythms and by physical exercise. Finally, from the post-analytical perspective, establishment of reliable reference ranges requires further efforts as the selection criteria for reference subjects should take into consideration new variables such as gender, race and vitamin D levels. Finally, clinical guidelines have recently revised and improved the criteria for a correct interpretation of PTH values.
Topics: Clinical Laboratory Techniques; Humans; Parathyroid Hormone
PubMed: 26035114
DOI: 10.1515/cclm-2015-0314 -
Indian Journal of Pediatrics Oct 1967
Topics: Humans; Parathyroid Hormone
PubMed: 5594839
DOI: No ID Found